Downgrading from Adaptive Server 15.5

Learn how to downgrade from Adaptive Server 15.5 to an earlier Adaptive Server 15.0, 15.0.1, 15.0.2 or 15.0.3 release. Downgrading to a 12.5.x or earlier release is not supported.

1. Save the current auditing settings for the 15.5 Adaptive Server by saving the output of the following command in all system and user databases where any auditing options have been turned on:

   1> sp_displayaudit
   2> go

2. Back up all of your databases and the $SYBASE release area prior to the 15.5 downgrade.
3. Start the 15.5 server in single user mode using dataserver -m option to guarantee that no other user can access Adaptive Server while you are going through the downgrade steps. See the Utility Guide for more details on starting the server in single user mode.
4. Make sure Adaptive Server 15.5 is prepared for downgrade by executing:

   sp_downgrade 'prepare', @toversion='version'

   The value of “version” may be written as “15.0”, “150”, “15.0.1”, “1501”, “15.0.2”, “1502", "15.0.3" or "1503.” However, the version entered should be the Adaptive Server version to which you want to downgrade.

   Note:

   If you have used the 15.0.2 features for encrypted columns and
   

   • You are reverting back to Adaptive Server 15.0 GA or Adaptive Server 15.0 ESD #1 you must specify the version as '15.0.'

   • You are reverting back to Adaptive Server 15.0, 15.0 ESD #2, 15.0.1, or a 15.0.1 ESD you must specify the version parameter as '15.0.1.'

   • You are reverting back to Adaptive Server 15.0.2 or a 15.0.2 ESD, you must specify the version parameter as '15.0.2.'

   sp_downgrade must be executed under master database.

   sp_downgrade 'prepare' validates the readiness of Adaptive Server 15.5 for downgrade. This means that sp_downgrade 'prepare' may print messages regarding manual changes required before the downgrade can be completed. Errors reported must be corrected and implications of warnings reported must be understood before you can proceed with further downgrade steps.

5. Repeat the last step until sp_downgrade 'prepare' reports no errors.
6. Begin the downgrade process by executing:

   sp_downgrade 'downgrade', @toversion='version',@override=1

   The version number should be the same as the version you entered above. Once the above command completes successfully there can be no more activity on the 15.5 server. You must run checkpoint and immediately shutdown the 15.5 server.

7. Copy the RUN_SERVER file to the 15.0, 15.0.1, 15.0.2 or 15.0.3 release area you are downgrading to. Modify the RUN_SERVER file to use the dataserver binary of the version to which you are downgrading. For example, if you are downgrading to 15.0.2 update 15.5 related information to 15.0.2 related information. From the SYBASE directory:

   /work_dirs/sybase/ase1502/ASE-15_0/bin/dataserver\
   -s OLD_SERVER_NAME\
   -d DOWNGRADED_MASTER_DEVICE\
   -e OLD_SERVER_LOG_FILE\
   -c OLD_SERVER_CONFIG_FILE\
   - M /work_dirs/sybase/ase1502\

   
   

   • Change the dataserver binary.

   • You can use -e, -c, -M option point to the old server.

8. Restart the old server using the modified RUN_SERVER file. Ensure that the environment variable points to the old server release such as $SYBASE, $SYBASE_ASE, or $SYBASE_OCS
   Note:

   When downgrading to a 15.0 or a 15.0.1 server, user passwords may be reset depending on the value of sp_passwordpolicy 'allow password downgrade'. If 'allow password downgrade' is set to '0', user passwords are reset and printed on the console. Be sure to save the output of sp_downgrade 'downgrade', <version> into a file. So the passwords are not lost. The old password do not work. Otherwise, you must restart the downgraded server with -psa to regenerate the sa password.

9. Run any scripts that may be applicable to your site listed in the post-downgrade tasks.

• Post-downgrade Tasks
  After you perform the basic downgrade steps, some changes from the 15.5 upgrade still persist.
• Additional Steps Required if You Used New Features
  If you used Adaptive Server 15.5 features that are not available in the Adaptive Server version to which you are downgrading, additional steps may be necessary before downgrading your server. In addition, some actions must be performed immediately after downgrading.
• If You Downgraded Back to the Original Installation After Upgrading to 15.5
  Look here to learn what to do if you upgraded to Adaptive Server 15.5, then downgraded back to the original version.